When examining the codons for the same amino acid, there is reduced specificity at the third position, known as third-base degeneracy. Describe an advantage to having third-base degeneracy and indicate how it may have arisen during evolution
What will be an ideal response?
Ans: Because of relaxed pairing constraints in the third position of the codon, the tRNAs for the same amino acid but having different anticodon sequences may recognize more than one codon. Also, the fact that similar amino acids tend to be represented by related codons reduces the effects of mutations because mutations in the third position either do not change the amino acid or change it to a chemically similar one. It is believed that the original organisms may have used a two base genetic code and therefore only the first two bases of the codon unambiguously specify a particular amino acid.
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14. One of the most critical pieces of evidence to the discovery of DNA structure was
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